The present invention relates to gauges, and more particularly to gauges for measuring gemstones in settings.
In the jewelry business, being able to accurately measure size and determine the value of gemstones is extremely important. Inaccurate measurements increase the cost of doing business. For loose gemstones, the task is generally easier. Simple gauges such as micrometers or calipers may be fitted around the gemstone and very accurate measurements of size taken.
A typical gauge used in the jewelry business includes a pair of arms capable of convergent and divergent motion and means to determine the separation or displacement between the arms. Each of the arms includes a projection or finger that extends towards the opposite arm and mates with the opposite projection. The gemstone is placed between the contact surfaces of the mating surfaces of the projections and the separation between the contact surfaces is determined.
Measuring the size of gemstones in a setting such as a ring, however, pose a significant problem. The adjacent prongs of the ring, which are holding the gemstone in place, interfere with the ability to fit the arms of the standard gauges around the gemstones. In some instances this problem is alleviated by the setting having an opening in its bottom to permit the insertion of one of the projections. In many other instances the intricate nature of the setting does not allow for such an opening and the use of a standard gauge is impractical without removing the gemstone from the setting. Short of removing the gemstone from the setting, an estimate must be made of the size of the gemstone.
The prior art includes several devices for the measurement of gemstones. Disclosed in U.S. Pat. No. 4,524,525, titled xe2x80x9cDiamond Gauge with Three-dimensional Stone Simulantxe2x80x9d and issued to Finkler, is a gauge having a stone simulant for sizing settings for small diamonds. This device determines the size of gemstone that will fit within a small setting. U.S. Pat. No. 4,107,850, titled xe2x80x9cStone and Mounting Gaugexe2x80x9d and issued to Adler, discloses a mounting gauge having a plurality of arms extending from a support assembly. Each of the arms has a disk like foot with each of the feet being successively larger. The feet may be inserted into a setting to make a comparison type measurement between the known size of the foot and the unknown size of the setting or gemstone.
The above art notwithstanding, people skilled in the art are working to develop devices for accurately measuring gemstones in their settings without requiring the removal of the gemstone from the setting or having to estimate the size of the gemstone.
According to the present invention, each of a pair of extensions for a gauge includes a sleeve and a member having a contact surface extending from the sleeve. The sleeve is sized to fit over the finger of the gauge and includes means to fixedly attach the sleeve to the finger. The contact surface extends outward along the member and the object to be measured by the gauge may be placed between the distal ends of the members. Extending the contact surfaces outward from the fingers permits measurement of objects by moving the contact surfaces and object laterally towards each other to bring them into proximity, and then converging the arms of the gauge until the contact surfaces engage the object and the measurement may be taken.
In one particular embodiment, at least one of the members is tapered in height and width. The tapering minimizes the size of the member at the distal end such that the tapered member will fit through the setting of a gemstone and may be engaged with the culet of the gemstone. The opposite member is engaged with the table of the gemstone and the size of the gemstone is thereby measured accurately without having to remove the gemstone from the setting. In another particular embodiment, both of the members are tapered in height and width. This particular configuration provides the benefit of being able to insert either or both of the members into the setting to measure the gemstone.
Although the invention was developed in the field of jewelry for measuring gemstones, it should be noted that the invention has application to other fields wherein the size of objects embedded within a structure is desired.
The foregoing and other objects, features and advantages of the present invention become more apparent in light of the following detailed description of the exemplary embodiments thereof, as illustrated in the accompanying drawings.